| Color Key | |
| Important key words or phrases. | |
| Important concepts or main ideas. | |
1. Learning Objectives and Review
1.1. Learning Objectives
- Gain an appreciation for the conservation issues for Black-footed ferrets
- Be familiar with the husbandry and preventative medicine recommendations of domestic ferrets
- Understand the reasons for neutering male and female ferrets
- Be able to recognize, diagnose and provide treatment options for the three main neoplastic diseases of domestic ferrets: insulinoma, hyperadrenocorticism and lymphoma
- Be able to recognize and provide treatment options for the major GI disorders of domestic ferrets
- Be familiar with the other common disorders of the domestic ferret mentioned in the text
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3. Basic Ferret Medicine and Surgery
Species: Mustela nigripes, Mustela putorius furo
Mustela nigripes is the black-footed ferret, our only native wild ferret. It is native to the Northwestern plains but is currently highly endangered and close to extinction. The black-footed ferret preys mainly on prairie dogs in the wild and often lives in old prairie dog burrows. Numbers have declined rapidly over the last century following agricultural development of the western plains and large scale poisoning (attempts at control) of prairie dog populations. Due to their severely endangered status the US Fish & Wildlife Service is coordinating a recovery program including a very successful captive breeding programs and recent attempts to reintroduce animals to previous habitat areas. Disease, management, and political problems continue to interfere with the reintroduction program. Mortalities most often involve canine distemper, plague or predator problems (coyotes). The goals of the recovery program are to establish a population of 1500 free living ferrets in 10 or more locations with a minimum of 30 breeding pairs per site (year 2010?).
Mustela putorius furo is the european ferret, related to the wild european polecat. The european ferret has been domesticated for 2,000 years. It was brought to North America by English settlers in the 17th century. It has been used for hunting, biomedical research and as a companion animal. There are an estimated 1 million pet ferrets in the US.
Domestic ferrets in the United States occur in two main coat colors: sable or fitch (wild type color) and albino (English). In addition there are over 30 color variations recognized among ferret fanciers.
Recognition of ferrets as legitimate pets has been a gradual process over the last 50 years. At this point in time ferrets are legal in every state except California and Hawaii, and New York City. They were declared legal in this state in February of 1996. Arguments against making ferrets legal included: their erroneous classification as a wild animal, concerns of establishing wild populations and displacing native wildlife, their reputation as "baby biters", and humane societies fears of another unwanted pet species they would have to deal with.
3.1. Basic physiologic and anatomic parameters
| Body weight range | 500-2,000 grams |
| Life span | 5-11 years (typically 6-8 years) |
| Age at weaning | 6-8 weeks |
| Reproductive maturity | first spring after birth |
| Gestation | 41 - 42 days |
| Body temperature (avg.) | 100.8-104F |
| Heart rate | 180-250 bpm |
| Respiratory rate | 33-36 per minute |
- In general, intact males are appreciably larger than intact females.
- Most neutered ferrets weigh 800-1200g. They may experience seasonal weight fluctuations due to deposition of subcutaneous fat in the winter.
- Ferrets may become very excited during a routine examination. An erratic heart rate will often be detected in this excited state. This is considered a normal finding and classified as a pronounced sinus arrhythmia.
FERRET DENTITION
|
 |
COMPLETE BLOOD COUNT (Normal mean values for Fitch or Albino ferrets)
| RBC | Male | Female | WBC | Male | Female |
| PCV (%) | 36-50 | 47-51 | WBC (103/μl) | 7.7 - 15.4 | 2.5 - 8.6 |
| RBC (106/μl) | 9.7-12.4 | NA | Neutrophil (%) | 24 - 78 | 12 - 41 |
| Hb (g/dl) | 12-16.3 | 15.2-17.4 | Lymphocyte (%) | 28 - 69 | 25 - 95 |
| MCV (fl) | 42 - 55.9 | NA | Monocyte (%) | 3.4 - 8.2 | 1.7 - 6.3 |
| MCHC (%) | 26.9 - 35 | NA | Eosinophil (%) | 0 - 7 | 1 - 9 |
| MCH (pg) | 14 - 16.4 | NA | Basophil (%) | 0 - 2.7 | 0 - 2.9 |
| Reticulocytes (%) (albinos) | 1-12 | 2-14 | Platelets (103/μl) (albinos) | 297 - 730 | 310 - 910 |
The PCV in a normal healthy ferret may be as high as 60-70%.. The WBC often runs significantly lower than expected in other carnivore species. Isoflurane may cause all values to be significantly decreased with 15 minutes due to splenic sequestration.
SERUM BIOCHEMISTRY (Normal values for the Fitch ferret)
| Chemistry compound | Mean value |
| Alk. Phos. (U/l) | 30 - 120 |
| ALT (U/l) | 82 - 289 |
| AST (U/l) | 57 - 248 |
| LDH (U/l) | 221 - 752 |
| Total protein (g/dl) | 5.3 - 7.2 |
| Albumin (g/dl) | 3.3 - 4.1 |
| Globulin (g/dl) | 1.8 - 3.1 |
| BUN (mg/dl) | 12 - 43 |
| Creatinine (mg/dl) | 0.2 - 0.6 |
| Total Bilirubin (mg/dl) | 0 - 0.1 |
| Glucose (mg/dl) | 62.5 - 134 |
| Cholesterol (mg/dl) | 119 - 209 |
| Triglycerides (mg/dl) | 10 - 32 |
| Sodium (mEq/l) | 146 - 160 |
| Chloride (mEq/l) | 102 - 121 |
| Potassium (mEq/l) | 4.3 - 5.3 |
| Calcium (mg/dl) | 8.6 - 10.5 |
| Phosphorus (mg/dl) | 5.6 - 8.7 |
Note the low creatinine levels compared with other carnivores. Normal bile acid levels have not been published for the ferret.
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3.2. Anatomic features
- The elongate body of the ferret allows for excellent abdominal palpation of most visceral organs.
- The spleen is often considered enlarged for a variety of reasons (see below).
- The chest is also elongated which places the heart somewhat more caudal than expected relative to dogs and cats.
- Other anatomical features are very similar to the cat.
- Intubation for anesthesia is not difficult.
- Venous access points are similar to those in a cat except that the jugular veins are located more laterally on the ventral neck than expected. In general, jugular or anterior vena cava venipuncture are preferred for blood sampling, and the cephalic or saphenous vein is preferred for intravenous catheter placement. Other venipuncture sites (not all suitable for pets) include the retro-orbital sinus, the caudal tail vein and a cardiac puncture.
- Male ferrets have an os penis and the penis is directed caudal as in a cat. The urethra is very difficult to catheterize (especially males neutered at a very young age). A 3.5 french urinary catheter or special catheter, available from Global Veterinary Products (Slippery Sam®), should be used.
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3.3. Reproduction
Jills, hobs and kits (also review Reproductive Physiology notes)
| Gestation | 41-42 days |
| Litter size | 1-18 (average 8) |
| Size at birth | 8-10 grams |
| Eyes open | 30-35 days |
| Weaning age | 6-8 weeks of age (300 grams) |
| Permanent canine teeth erupt | 52 days |
| Deciduous canine teeth lost | 56-70 days |
- Ferrets reach sexual maturity normally in the first spring after birth.
- They are seasonal breeders with a breeding season from December-July (hob), and March-August (jill).
- The female is an induced ovulator and will remain in estrus for long periods of time if not allowed to breed.
- Ferrets not used for breeding should be neutered to avoid estrogen toxicity (see below).
- At the large ferret breeding farms, ferrets are neutered and descented at 6 weeks of age.
3.4. Nutrition
The exact nutrient requirements of ferrets are pretty well understood. They are carnivores with dietary needs similar to cats and mink. Their protein requirements are in fact higher than the cat (recommended protein: 30-40% DM with a recommended fat content of 18-30% DM; 18-20% fat for nonbreeding ferrets). In general, ferrets are given formulated ferret diets or high-quality animal protein based kitten foods.
3.5. Husbandry and Behavior
Pet ferrets are usually housed in a cage with a private "den" area. They spend a good deal of their time sleeping in the den. They can be housed in groups. Ferrets can also be caged outdoors but require adequate shelter and shade. They are prone to heat exhaustion since they do not have well developed sweat glands. Ferrets are easily trained to a litter box similar to a cat. It is advisable to keep them caged when unsupervised. They will often get into unexpected places and will readily swallow a variety of foreign objects! They will also tend to hoard things that they like and will stash their hoard in one or several places (e.g. under the refrigerator). It is not advisable to keep ferrets as pets in households with infants.
3.6. Basic therapeutic approaches
- Intravenous catheters - Jugular catheters are difficult to place and this vein is best saved for obtaining blood samples. Short catheters (Jelco) can be placed relatively easily in either the cephalic or lateral saphenous veins.
- Intraosseous catheters work just as well as intravenous catheters and are useful in many situations, especially when IV access has failed. A 20 or 22 ga. spinal needle can be placed in the femur.
- IM and SQ injections are given as in dogs and cats
 Thoracocentesis in a ferret with pleural
effusion
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3.7. Anesthesia and surgery
There are many surgical diseases in the ferret. Consequently sedation and anesthesia are frequently performed in a variety of situations. Pre-anesthetic workups and health status concerns are the same as for dogs and cats.
3.7.1. Sedation
Sedation may be indicated for adequate restraint for short procedures such as venipuncture, radiographs, or ultrasound examination. Sedation is usually accomplished with an intramuscular injection of ketamine combined with diazepam (see below).
3.7.2. Tranquilization
Tranquilization or short anesthesia may be utilized for induction of inhalation anesthesia, short surgical procedures such as castration, skin tumor removal, or dentistry. Ketamine combined with xylazine is usually used in these cases, with the option of adding inhalation anesthetics if needed.
3.7.3. Anesthesia
Anesthesia for a variety of major surgical procedures is often performed. Isoflurane gas is most often used. Intubation is easily and routinely performed.
| Common Anesthetic Doses for Ferrets | |
| Ketamine (sedation) | 10-20 mg/kg IM |
| Diazepam | 1-2 mg/kg IM, IV |
| Midazolam | 0.1-0.5 mg/kg IM |
| Ketamine/diazepam | 10-30/2-3 mg/kg IM |
| Ketamine/xylazine | 10-30/1-4 mg/kg IM |
| Telazol | 22mg/kg IM |
3.7.4. Surgery
Surgery as indicated below is often required in ferrets. Health concerns pre-operatively are similar to those in cats and dogs. It should be noted that ferrets often have multiple problems occurring simultaneously and a full evaluation of the animal should be performed before proceeding with surgery for any particular condition. Heart disease, various endocrine disorders, and lymphoproliferative diseases can seriously affect any surgical procedure.
Perioperative management of the surgical patient is also similar to cats and dogs, and is very important. Only their small size makes the ferret a little more challenging.
Surgical protocols for gastrotomy, abdominal surgery, orthopedics, tissue handling, suture etc. are similar to other carnivore species (dogs, cats), taking into account the ferrets very small size.Ferret spay, castration and anal sacculectomy are commonly performed when the animals are very young. Neutering is similar to a cat. Anal sacculectomy will reduce the ferret odor, but will not eliminate it.
 Perineal area in a male ferret in preparation for
castration
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3.8. Preventative medicine
3.8.1. Vaccinations
Only use products approved for ferrets.Vaccinations should be performed regularly as indicated to protect against canine distemper and rabies viruses. Vaccines are often given separately because vaccine reactions have been seen fairly frequently, especially with the Fervac D. Reactions range from injection site irritation to full blown anaphylaxis and even death. Fewer reactions are expected with the new vaccine. Owners should be warned of the possibility of a reaction and are often asked to stay in the veterinary clinic for 30 minutes following a vaccination. Ferrets are exquisitely sensitive to canine distemper virus. Timing of vaccinations is important because it has been shown that kits are refractory to vaccination until 36-47 days of age. Ferrets are not susceptible to feline panleukopenia or rhinotracheitis, mink virus enteritis, canine hepatitis or canine parvovirus.
-
Canine distemper
- Purevax D (Ferret Approved, recombinant canarypox vectored nonadjuvant vaccine)
- Fervac-D (Ferret Approved, modified-live non-ferret origin, not recommended, United Vaccines, Madison, WI)
- 8 weeks, then every 3 weeks for at least 2 boosters then annually
-
Rabies
- Imrab (Rhone-Merieux)
- 3 months of age, then annually
3.9. Common problems/diseases
3.9.1. Viral diseases
3.9.1.1. Canine distemper
- Highly susceptible to infection with mortality approaching 100%
- Incubation period 7-10 days
- Clinical signs: anorexia, pyrexia, nasal and ocular discharge (often mucopurulent), chin rash, photophobia, generalized dermatitis, hyperkeratotic foot pads
- Neurologic signs seen in ferrets that survive the catarrhal phase
- Diagnosis: clinical signs, FA test on blood smear, histopath
- Treatment: supportive, hyperimmune serum (?) - euthanasia generally advisable
- Prevention with vaccination is essential!
3.9.1.2. Influenza virus
- Human influenza virus: many strains (usually influenza A)
- Transmission: human to ferret (usually) and ferret to human
- Clinical signs: lethargy, pyrexia, sneezing, coughing, nasal discharge, conjunctivitis
- R/O early signs of distemper
- Symptoms last 5-14 days
- Treatment: symptomatic - can use pediatric cough suppressants and antihistamines
3.9.1.3. Aleutian disease virus
Aleutian disease is a parvovirus causing persistent viremia in mink and in ferrets. Mink are very susceptible, while ferrets are often carriers of the disease, but some will become affected. The ferret strains of this virus are likely mutations of the mink virus. In Mink, susceptibility is related to genetics and the disease produces immune mediated glomerulonephritis. Do not house ferrets with mink
In ferrets:
- many are asymptomatic, subclinical
- wide variety of clinical syndromes reported : chronic wasting, weight loss, weakness, ataxia, progressive posterior paralysis, muscle wasting, tremors
- may be associated with splenomegaly, hepatomegaly
- diagnosis based on hypoalbuminemia and hypergammaglobulinemia (20-60% of total protein) and serology (United Vaccines, Madison WI; Avecon Diagnostics)
- treatment: none
3.9.1.4. Epizootic Catarrhal Enteritis (ECE)
- "Green slime diarrhea"
- Coronavirus, highly contagious
- Vomiting, dehydration and profuse diarrhea with mucous ; older ferrets most severely affected
- Diagnosis based on history (new animal?), clinical signs and ruling out other diseases
- Treatment includes supportive care : fluids, antibiotics for secondary bacterial infections, and a bland diet.
3.9.2. Bacterial diseases
Bacterial diseases of major concern are discussed below. Some other reported diseases include: salmonellosis, leptospirosis, listeriosis, atypical tuberculosis, botulism, and subcutaneous abscesses.
3.9.2.1. Bacterial pneumonia
- relatively uncommon
- seen usually secondary to megaesophagus (rare condition)
- Streptococcus zooepidemicus, E. coli, Klebsiella pneumoniae, Pseudomonas, Bordetella
3.9.2.2. Helicobacter mustelae
- Chronic gastritis and gastric and duodenal ulcers
- Clinical signs often vague: lethargy, anorexia, hypersalivation, tooth-grinding, halitosis, melena
- Ferrets used as experimental model for Helicobacter pylori in humans
- Diagnosis: often difficult may require barium series, endoscopy or exploratory surgery
-
Treatment: triple therapy as in
humans
Treatment for Helicobacter in ferrets (tx. 2 weeks) Clavamox 20 mg/kg q12h Metronidazole 20 mg/kg q12h PeptoBismol 17 mg/kg (1 ml/kg) q12h or Sucralfate 100 mg q 8h
3.9.2.3. Proliferative Bowel Disease (PBD)
- Similar to proliferative enteropathy of swine and proliferative ileitis of hamsters (same organism)
- Lawsonia intracellularis
- Typically a disease of young ferrets (<14 months of age), variable susceptibility
- Clinical signs: diarrhea, sometimes with blood, rectal prolapse, pyrexia, inappetence, diarrhea may be intermittent or persist long-term
- Diagnosis: usually based on clinical signs and response to therapy
- May be able to palpate thickened gut
- Histopathology (silver stains, Giemsa) shows proliferation of mucosal cells, intracellular organisms
- Treatment: chloramphenicol 50 mg/kg q12h x 2 weeks minimum, may relapse or may not respond
| Major Rule-outs for Ferret Gastroenteritis | |
| Helicobacter | Cryptosporidiosis |
| ECE (coronavirus) | Coccidiosis |
| Inflammatory bowel disease | GI foreign body |
| Proliferative bowel disease | Lymphoma |
3.9.3. Fungal diseases
Blastomycosis, cryptococcosis and histoplasmosis have been reported. Dermatophyte infections most frequently involve Microsporum canis. Diagnosis and treatment is as for the cat.
3.9.4. Parasitic diseases
As in other carnivores, fleas and ear mites can be found on ferrets, and are contagious among other household pets (cats and dogs). Treatment is the same as for cats. Gastrointestinal parasites are not commonly seen. Cryptosporidiosis has been reported and may be zoonotic. Coccidia or Giardia are occasionally diagnosed in young ferrets.
3.9.4.1. Scabies
- Sarcoptes scabei
- signs: alopecia, pruritus
- diagnosis: clinical signs, skin scraping
- treatment: ivermectin 0.4 mg/kg SC once; repeat in 2 weeks ; selemectin has also been used
3.9.4.2. Heartworm - Dirofilaria immitis
- Can be severe disease in ferrets, may involve only 1 worm - easier to prevent than to treat
- Prevention: ivermectin, 1/4 smallest available canine/feline tablet
- Clinical signs: (pre-caval syndrome) fulminant cardiac failure with lethargy, tachypnea, dyspnea, cough, ascites, melena
- Diagnosis: clinical signs, radiographs, cardiac ultrasound, ELISA to test for HW antigen (Snap Heartworm Antigen Test Kit, IDEXX Labs, Inc.)
- Rarely become microfilaremic
- Treatment: may be successful if detected early; PROGNOSIS GUARDED. Safety and efficacy of melarsamine has not been established, although mortalities have been reported in North American river otters and red panda with this drug.
| Suggested treatment protocol for heartworm positive ferret | |
| Ivermectin to resolve microfilaremia (if present) | 50 μg/kg SQ q 30d |
| Melarsamine, single dose | 2.5 mg/kg IM |
| Melarsamine, follow-up doses 1 month later | 2.5 mg.kg IM x 2 ; 24 hours apart |
| Prednisone during therapy | 0.5 mg/kg PO q 12-24 h. |
| Treat as necessary for cardiac failure, restrict to cage rest | |
| Perform follow-up ELISA 3 months after adulticide therapy, then monthly until negative | |
3.9.5. Neoplastic diseases
Neoplastic disorders are the most common diseases seen in the domestic ferret. In-breeding with limited genetic stock has likely artificially produced this trend. Many of the neoplastic diseases are not characteristic of their counterparts in other carnivores (dogs and cats).
Some Neoplasias Reported in the European Ferret
| Tumor type | Location | Age |
| Squamous cell carcinoma | Multiple | 3-5 yrs |
| Basal cell carcinoma | Multiple | 3+ yrs |
| Ceruminous gland adenocarcinoma | Ear (base) | 7 yrs. |
| Sebaceous carcinoma | Tail and perineum | 6+ yrs |
| Adenocarcinoma | Prepuce, Perianal gland, Liver, Pancreas (exocrine), Stomach, Adrenal cortex | 4 yrs 2+ |
| Insulinoma | Pancreas (β-cell) | 3+ |
| Bile Duct Cystadenoma | Liver | Adult |
| Cortical adenoma | Adrenal gland | 2+ yrs |
| Transitional cell carcinoma | Kidney | 2 yrs |
| Mastocytoma | Multiple | 3+ yrs |
| Myxosarcoma | Thorax, tail | |
| Chordoma | Caudal, cervical spine | 4 yrs |
| Chondroma, Chondrosarcoma | Tail tip | NA |
| Osteoma | Base of skull, larynx, vertebrae | 5 yrs |
| Rhabdomyosarcoma | Thorax | 1 yr |
| Neurofibroma, Neurofibrosarcoma | Neck, Eyelid | |
| Papillary cystadenoma | Kidney | Adult |
| Papillary cystadenocarcinoma | Mammary | 12+ |
| Theca cell, granulosa cell tumor | Ovary | 3 |
| Fibroma, fibromyoma, myoma | Ovary | Adult |
| Leiomyoma | Ovary, Uterus | 1-5 yrs |
| Interstitial cell tumor, Sertoli cell tumor | Testes | 6 yrs |
| Hemangioma, hemangiosarcoma | Spleen, liver, leg | 2-5 yrs |
| Lymphosarcoma complex | Multiple | 6 mos+ |
| Myeloma | Lumbar spine | 3 yrs |
| Sarcoma | Orbit | |
| Myelosarcoma | Skin | |
| Mesothelioma | Abdomen | 1.5+ yrs |
| Histiocytoma | Thorax |
3.9.5.1. Mast cell tumors
- Common benign skin tumors; visceral mast cell tumors are rare and do not occur with cutaneous tumors ; very different ds. from the dog!
- Clinical signs: small round raised tan lesions anywhere on the body, with or without pruritis or alopecia
- Diagnosis: physical appearance of the lesion, excisional biopsy
- No special treatment is required following excision
- Monitor any unexcised lesions
3.9.5.2. Insulinoma
- Seen in middle-aged to older ferrets (3 years and older, typically 5-6 yr)
- Very common: assume all ferrets 5 years or older have insulinoma until proven otherwise!
- Clinical signs: episodic weakness or collapse (minutes to hours), hind limb paresis, abnormal mentation, hypersalivation, pawing at the mouth
- Seizures uncommon but do occur
- Common emergency call!
- Diagnosis: hypoglycemia <60 mg/dL; hyperinsulinemia >250 pmol/L (>35 μU/mL)
- Surgical treatment: remove all nodules (histology: hyperplasia, adenoma, adenocarcinoma)
- Medical treatment: prednisone 0.5-2 mg/kg q12h (start low), later add diazoxide 5-30 mg/kg q12 h (start low)
- Prognosis guarded: survival rates vary from 1 month to 1+ years
- Surgery is often palliative, but rarely curative: microscopic neplasia and metastasis have probablyoccured at time of surgery
3.9.5.3. Hyperadrenocorticism
- Extremely common, ages 3 and up
- Very different disease than seen in the dog (Cushing's)
- Mostly androgen secreting tumors ; influence of early
neutering?
- Hypothesis that early neutering and domestication have interfered with the normal hormonal feedback mechanisms (highly seasonal animals) and produced animals under constant hormonal stimulation. This triggers hyperplasia >>adenoma >> adenocarcinoma in other animals, and is possibly related to high rate of adrenal tumors, insulinoma, mast cell tumors and lymphomas in ferrets (For more on this go to Nico Schoemaker chapter).
- Adrenal cortical hyperplasia, adenoma, and adenocarcinoma
-
Clinical signs: vulvar swelling in females,
symmetric hair loss beginning on the tail and spreading up the trunk, pruritus
(PU/PD, pendulous belly uncommon), anemia very rare, stranguria or urinary
obstruction in males
- Prostatic enlargement (hypertrophy, cysts, prostatitis) secondary to adrenal neoplasia is a common cause of partial or complete urethral obsruction in male ferrets. Emergency treatment is often necessary to relieve an acute obstruction. Urethral catheterization is challenging: a special urinary catheter is available from Global Veterinary Products (Slippery Sam®). Adrenalectomy usually reduces prostate size within days, but complicated cases involving infection will be more difficult to deal with.
- Diagnosis: clinical signs, adrenal ultrasonography, sex steroid hormone analysis (estradiol, androstenedione, 17-hydroxyprogesterone, estradiol: University of Tennessee)
- ACTH stimulation and dexamethasone suppression tests rarely helpfulWHY?
-
Surgical treatment is the preferred
therapy: adrenalectomy, cryosurgery
- Major risks associated with R adrenalectomy and its relationship with the vena cava
- Have blood transfusion (buddy) or oxyglobin on hand
- Medical treatments are only temporary and reduce
clinical signs but do not effect tumor growth,
- GnRH analogs (lupron) - down regulates GnRH receptors
- Androgen receptor blockers (Flutamide) - only works in some ferrets
- Aromatase inhibitors (Arimidex) - blocks production of estrogen
- Ketoconazole and Lysodren are not effective
 |
 |
3.9.5.4. Lymphoma
- One of the most common neoplasms (following insulinoma and adrenal tumor)
- Fulminant aggressive disease in juvenile
animals
- may affect different organs: liver, spleen and thymus >>>bone marrow
- Acute clinical signs may include pleural or abdominal effusion, leukemia
- Response to tx. poor, prognosis poor
- Smoldering, chronic disease in older animals
2-9 years of age
- chronic, cyclical ds.
- lethargy, inappetance, weight loss
- lymphadenopathy most common form detected on exam - R/O prominent fat pads!
- Prognosis better than juvenile disease, may respond to minimal prednisone therapy
- Diagnosis: tissue biopsy for definitive diagnosis (eg, lymph node, fluid aspirate, etc.)
- Treatment: chemotherapy protocols as for other animals ; many available in the literature
 Mediastinal lymphoma in a ferret
|
3.9.6. Estrogen toxicity due to prolonged estrus
- Seen in approx. 50% of unspayed females if not bred, uncommon now that most pet ferrets neutered at 6 wks
- Clinical signs: inappetence, lethargy, melena
- Physical exam: swollen vulva, pallor, petechiae, ecchymoses
- Diagnosis: PCV, CBC, platelet count
-
Prognosis varies according to PCV
- grave if PCV <15%
- guarded if PCV 16-24%
- Treatment: varies according to stage of disease
- if adequate PCV and platelet count: ovariohysterectomy
- safer approach in most cases: induce ovulation with human chorionic gonadotropin 100 IU or 1,000 USP units IM (functions only after day 10 of estrus) ; may need repeat injection in 7-14 days
- Other therapy: blood transfusion(s), iron, androgens, steroids, antibiotics
 Vulvar swelling in response to estrogen in the
female ferret
|
3.9.7. Cardiomyopathy
- Seen in middle-aged ferrets
- Clinical signs variable: lethargy, inappetence, dyspnea, coughing, ascites
- Dilatative cardiomyopathy most common
- Diagnosis and treatment: as for cats
- Echocardiogram, radiographs, ECG
- Acute: Oxygen, diuretics, nitroglycerin,
- Chronic or stabilized: Diuretics, ACE inhibitors, digoxin
- Prognosis good with therapy (better than dogs and cats)
3.9.8. Noninfectious GI disorders
3.9.8.1. Inflammatory Bowel Disease
- Lymphoplasmacitic and eosinophilic
- May be complication associated with other chronic disease (other GI diseases, lymphoma, megaesophagus)
- Clinical signs
- Abnormal stool
- Thin, poor muscle mass
- Nausea, vomiting, regurgitation
- Prominent mesenteric lymph nodes
- Elevated serum lipase, globulins, liver enzymes
- Diagnosis through history and clinical presentation, bloodwork, intestinal and lymph node biopsy
- Treatment includes anti-inflammatories (azathioprine, prednisone, etc.) and treating other associated conditions
3.9.8.2. Splenomegaly
- Common physical finding in ferrets
- Reported causes in ferrets:
- lymphoma
- plasma cell myeloma
- megakaryocytic myelosis
- Aleutian disease virus infection
- chronic helicobacter
- idiopathic hypersplenism
- Found often in association with insulinoma and adrenal disease
- May not be associated with clinical signs
- Recommended work-up: CBC, platelet count, reticulocyte count if indicated, splenic aspirate
- Look for other diseases: serum chemistry, urinalysis, radiographs, cardiac or endocrine evaluation
- Treatment and prognosis: depend on primary disorder if any determined
- Splenectomy indicated only if: rupture, neoplasia, true hypersplenism
3.9.8.3. Gastrointestinal foreign bodies
 Gastrotomy to remove a foreign body in a
ferret
|
- Very common because of ferrets' inquisitive nature
- Rubber FB most common in younger animals (ear plugs, toys, etc.)
- Trichobezoars seen in older animals
- Clinical signs: chiefly anorexia also vomiting, melena, weight loss
- Diagnosis: palpation, radiography
- Treatment: surgery immediately
3.9.9. Urinary tract disorders
3.9.9.1. Urethral obstruction/Urolithiasis
- Both sexes affected
- Struvite calculi most common
- Role of diet?
- urine pH should be about 6.0 on a good meat-based diet
- urine pH is higher on poor-quality diet with plant protein (eg, corn, cat food diets)
- pH > 6.4 predisposes to struvite urolithiasis
- Diagnosis: clinical signs, palpation, radiographs, urinalysis
- Treatment: surgical removal of uroliths, urethral catheterization may be difficult, use antibiotics as necessary and correct diet (gradually) emergency perineal urethrostomy may be required
-
REMEMBER: stranguria is most often associated
with hyperadrenocorticism and prostate enlargement -
- Adrenalectomy resolves (1-2 days)
- Aspirate prostate during surgery to relieve pressure and re-establish patent urethra
DIAGNOSTIC TIP: Middle-age to older ferrets often have more than one "important" disease concurrently. KEEP YOUR EYES OPEN FOR MORE THAN ONE PROBLEM!
4. Ancillary Material
4.1. Readings
4.1.1. Texts and Articles
Beeber, Neal L. and Holly S. Mullen. Abdominal and miscellaneous surgery in ferrets. IN Veterinary Clinics of North America Exotic Animal Practice, 3:3, 2000 : 647-671.
Besch-Williford CL. Biology and medicine of the ferret. Vet Clin NA: SAP 1987;17(5):1155-1183.
Burgess, Mark and Michael Garner. Clinical aspects of inflammatory bowel disease in ferrets. Exotic DVM 4.2, 2002 : 29-34.
Fox JG. Biology and Diseases of the Ferret, 2nd ed.. Philadelphia:Williams & Wilkins, 1998.
Fudge, Alan M. Laboratory Medicine, Avian and Exotic Pets. Philadelphia : W.B. Saunders Co., 2000.
Hillyer, Elizabeth V. and Katherine Quesenberry. Ferrets, Rabbits and Rodents. Philadephlia: WB Saunders Co., c1996.
Johnson-Delaney, Cathy A. Exotic Companion Medicine Handbook for Veterinarians. Wingers Pub. Inc., 1996.
Johnson-Delaney, Cathy A. Update on ferret adrenal research. Exotic DVM 4.3, 2002 : 61-64.
Lair, Stephane. Pathology and epidemiology of neoplasia in the captive population of black-footed ferrets (Mustela nigripes). Proc. of the Joint Conference of AAZV and AAWV, 1998.
Mann FA et al. Reference intervals for insulin concentrations and insulin:glucose ratios in the serum of ferrets. Journal of Small Exotic Animal Medicine, 2 (2), 1993, pp. 79-83.
Marini, RP, et al. Functional islet cell tumor in six ferrets. JAVMA, 202 (3), 1993, pp.430-433.
Morrisey, James K. and Jan C. Ramer. Ferrets : clinical pathology and sample collection. IN Veterinary Clinics of North America Exotic Animal Practice, 2:3, 1999 : 553-564.
Neiffer, Donald L., et al. Mortality associated with melarsomine dihydrochloride administration in two North American river otters and a red panda. Journal of Zoo and Wildlife Medicine 33 (3), 2002 : 242-248.
Nelson WB. A simple method for removal of ferret musk glands. Avian/Exotic Prac 1985;2(4):6-10.
Neuwirth, L., et al. Adrenal neoplasia in seven ferrets. Veterinary Radiology & Ultrasound, 34 (5), 1993, pp.340-346.
Orcutt, Connie. Treatment of urogenital disease in ferrets. Exotic DVM 3.3, 2001: 31-37.
Palley, Lori S. Parvovirus-associated syndrome (Aleutian disease) in two ferrets. JAVMA, 201 (1), 1992, pp.100-106.
Rosenthal, K., et al. Hyperadrenocorticism associated with adrenocortical tumor or nodular hyperplasia of the adrenal gland in ferrets. JAVMA, Vol. 203 (2), 1993, pp. 271-275.
Shoemaker, Nico J., et al. Correlation between age at neutering and age at onset of hyperadrenocorticism in ferrets. JAVMA, 216 (2), 2000: 195-197.
Thorne, ET, Williams ES.1988. Disease and endangered species: the black-footed ferret as a recent example.Cons.Biol.2(1):66-74.
Wagner, Robert A., et al. Leuprolide acetate treatment of adrenocortical disease in ferrets. JAVMA, 218 (8), 2001: 1272-1274.
Weiss, Charles A., et al. Surgical treatment and long-term outcome of ferrets with bilateral adrenal tumors or adrenal hyperplasia: 56 cases (1994-1997). JAVMA, 215 (6), 1999: 820-823.
Weiss CA. Cryosurgery of the ferret adrenal gland. Exotic DVM Magazine, 1 (5), 1999: 27-28.
Wimsatt, Jeffrey, et al. Efficacy of a commercial canine distermper vaccine in the domestic ferret (Mustela putorius): survival, PCR, and serologic evidence. Proceedings of the AAZV and IAAAM Joint Conference, 2000. pp. 238-239.
Xiantang, Li, et al. Neoplastic diseases in ferrets: 574 cases (1968-1997). JAVMA, Vo. 212 (9), 1998, pp. 1402-1406.
4.2. Websites
Association of Exotic Mammal Veterinarians (AEMV) http://www.aemv.org/
Ferret Health Care website http://www.miamiferret.org/fhc/index.html
Ferret Pathology Website http://www.afip.org/ferrets/index.html
Black Footed Ferret Recovery Program website http://www.blackfootedferret.org/
US Fish and Wildlife Service site on the Black footed ferret https://ecos.fws.gov/species_profile/SpeciesProfile?spcode=A004
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